1. Field of the Invention
The present invention relates to an ink jet recording method, and more particularly to an ink jet recording method wherein a reaction solution and an ink composition are deposited on a recording medium having no ink composition absorbing capacity to perform printing.
2. Background Art
Ink jet recording is a printing method wherein droplets of an ink composition are ejected and deposited onto a recording medium to perform printing. This method has a feature that images having high resolution and high quality can be printed at a high speed by means of relatively inexpensive apparatuses. In general, the ink composition used in the ink jet recording comprises water as a main component and, added thereto, a colorant and a wetting agent, such as glycerin, for preventing clogging and other purposes.
Recording media, such as papers, absorb the ink composition to permit the colorant to penetrate into and to be fixed onto the recording media.
On the other hand, plastic films, such as OHP sheets, do not inherently absorb the ink composition. Thus, for ink jet recording on the recording medium having no ink composition absorbing capacity, the ink composition should be strongly fixed onto the surface of the recording medium. The ink composition that is not strongly fixed forms images having poor rubbing/scratch resistance. Further, when an ink composition composed mainly of water is used, the time required for the formed image to be fixed onto the recording medium, that is, the drying time, is preferably short. This is because the long drying time may cause a fear that the image is deteriorated upon contact of the image with members within a printer or upon contact of the image with a hand or the like after a discharge from the printer. Further, in the case of printing on recording media having no ink composition absorbing capacity, a solvent added to the ink composition should be selected so that the recording medium neither undergoes a change in quality nor is deformed by the solvent contained in the ink composition.
On the other hand, regarding the ink jet recording method, the application of a polyvalent metal salt solution onto a recording medium followed by the application of an ink composition containing a dye having at least one carboxyl group has been recently proposed (for example, Japanese Patent Laid-Open No. 202328/1993). The claimed advantage of this method is that the polyvalent metal ion combines with the dye to form an insoluble complex, the presence of which can offer an image having water fastness and high quality free from color bleeding.
Further, the use of a color ink comprising at least a surfactant for imparting a penetrating property or a solvent having a penetrating property and a salt in combination with a black ink capable of being thickened or agglomerated through the action of the salt has been proposed in the art (Japanese Patent Laid-Open No. 106735/1994). The claimed advantage of this method is that high-quality color images having high image density and free from color bleeding can be yielded. Specifically, an ink jet recording method has been proposed wherein two liquids, a first liquid containing a salt and a second liquid of an ink composition, are printed to realize good images.
Other ink jet recording methods, wherein two liquids are printed, have also been proposed, for example, in Japanese Patent Laid-Open Nos. 240557/1991 and 240558/1991.
The present inventors have now found an ink jet recording method, using two liquids, which can realize good images on recording media having no ink composition absorbing capacity. The present invention has been made based on such finding.
Accordingly, it is an object of the present invention to provide an ink jet recording method, using two liquids, which can realize good images on recording media having no ink composition absorbing capacity.
According to one aspect of the present invention, there is provided an ink jet recording method comprising the steps of: depositing a reaction solution and an ink composition onto a recording medium to perform printing,
wherein the recording medium does not substantially absorb the ink composition;
the reaction solution comprises a reactant which, when brought into contact with the ink composition, produces coagulate; and
the ink composition comprises a pigment and resin emulsion having a minimum film-forming temperature of 20xc2x0 C. or below, the content of the polymer particulates in the ink composition being not less than 5% by weight, the weight ratio of the polymer particulates to the pigment being 1 to 20.